Furnace



May 7, 1957 K. H. HUPPERT FURNACE Filed April 29, 1953 27 ff 2, A mz' l t l 25 im.' 23 1.' 20 l United States Patent O FURNACE Karl Henry Huppert, Chicago, Ill.

Application April 29, 1953, Serial No. 351,921

2 Claims. (Cl. 263-15) This invention relates to a furnace having an improved construction for providing la vacuum or a desired supply of gas.

Among the objects of my invention is to provide a furnace having a heating chamber and an auxiliary cham ber spaced by porous heat resistant insulating material to permit the atmosphere to be withdrawn from the heating chamber and cooled by delayed passage through the porous material and the auxiliary chamber before passing out of the furnace and thereby resulting in saving of the withdrawal means.

Another `object is to permit gas or air to be admitted into the heating chamber after its admission has been delayed due to passage lthrough the auxiliary chamber and the porous material, thereby preventing harming or injuring material being tired or heated due to sharp temperature changes.

My invention also contemplates such other objects, advantages as will more fully appear and which are inherently possessed by my invention.

While I have shown in the accompanying drawing preferred embodiments of my invention, yet I wish it understood that the same are susceptible of modification and change without departing from the spirit of my invention.

Referring to the drawings, Fig. 1 is a sectional view of my furnace;

Fig. 2 is a partial sectional view of another embodiment of my invention.

A preferred embodiment selected to illustrate my invention comprises a casing of steel or other suitable material having a door 11 with an enlarged backing 12 of brick or other suitable heat resistant insulating material and a seal 13. Inside the hollow interior of the casing 10 is a thick lining 14 of brick or other suitable heat resistant insulating material. When door 11 is closed, lining 14 and backing 12 surround furnace chamber 15. A plurality of spaced heat producing elements or members 16 are positioned in lining 14 adjacent chamber 15. Electric wire 17 extend from heat producing members 16 through lining 14 and casing 10 to an electric source of supply. Within casing 10 adjacent one extremity thereof angle irons or other suitable supports 18 are attached to support wall 19 of brick -or other suitable porous heat resistant insulating material, leaving plenum or auxiliary chamber 20.

A conduit 21 leads through casing 10 into auxiliary chamber 20. The other end :of conduit 21 leads to a vacuum pump 22 or other suitable vacuum producing means with a valve 23 therebetween. Another passage 24 leads to gas supply member 25 and valve 26 therebetween.

In use, the articles, or material to be heated or fired are placed through door 11 into chamber 15 and the door is closed and sealed by seal 13. Heat is obtained from heat producing members 16 by operation of external controls. Vacuum pump 22 is operated to pull the air out of auxiliary chamber 20. Because wall 19 and lin- ,ing 14 are made of porous material, the air in chamber f Patented May 7, 1957 15 is sucked therethrough into chamber 20 and out through conduit 21 to eventually provide chamber 15 with -a substantial vacuum. Because the heated air withdrawn from chamber 15 has to go through lining 14, wall 19 and auxiliary chamber 20, it is cooled so as not to damage conduit 21, valvek 23, and vacuum pump 22. This results in great saving to this equipment and in its greater operating efciency and longer life.

When desired, valve 23 may be closed and vacuum pump 22 stopped. Valve 26 may be opened and gas or air from supply member 25 permitted to flow into passage 24, conduit 21, auxiliary chamber 20, wall 19, and through lining 14 into chamber 15. Because of this filtering of the gas or air, its passage is slowed to permit its heating on the way so as not to harm or injure any articles or material being tired or heated in chamber 15 due to quick changes of temperature.

In another embodiment shown in Fig. 2, I provide a conduit 21 leading from auxiliary chamber 20 to vacuum producing member 22 with suitable valve 23 therebetween, and another conduit 27 leading from the auxiliary chamber 20 to a gas or air supply member 25, with valve 26 therebetween.

Having thus described my invention, I claim:

l. A furnace `comprising an outer hollow steel casing having front, rear, bottom, top and spaced side portions, said front portion having an opening, a door movably attached to said front portion for closing the opening, a thick backing of heat resistant brick material attached to the rear surface of said door, a thick lining of heat resistant porous brick material attached to the inner surface of said front portion and to the forward inner surfaces of said top, bottom and spaced side portions, the inner surfaces of said lining and said backing defining a hollow heating chamber in which articles are to be heated, a plurality `of heating elements positioned in said lining adjacent the heating chamber and having means leading out of said casing to a source of power and 'to external controls, a wall of heat resistant porous brick material contacting the rear surface of said lining and attached to the rear inner surfaces of said top, bottom and spaced side portions and defining therewith and with the rear portion of casing a hollow single rear plenum chamber of substantial size, the plenum chamber being located only to the rear of the heating chamber, a conduit leading on one end into the plenum chamber, a vacuum producing member attached to the other end of said conduit and adapted to pull air out of the heating chamber through said lining and said wall into the plenum chamber and then into said conduit, said lining, said Wall and the plenum chamber adapted to cool the air passing rearwardly from the heating chamber to the plenum chamber before it reaches said conduit to prevent damage thereto.

2. A furnace comprising an outer hollow steel casing having la front opening, a door movably attached to said casing for closing the opening, a thick backing of heat resistant brick material attached to the rear surface of said door, a thick lining of heat resistant porous brick material positioned within the front portion of said casing, the inner surface of said lining and said backing dening a hollow heating chamber in which articles are to be heated, a wall of heat resistant porous brick material positioned within said casing behind said lining and separating the portion of the casing to its rear into a hollow rear plenum chamber located only to the rear of the heating chamber, said plenum chamber of substantial size, a conduit leading on one end into the plenum chamber, a vacuum producing member attached to the other end of said conduit and adapted to pull air out of the heating chamber through said lining and said wall into the plenum chamber and then into said conduit,

ICC

References Cited in the lc of this patent UNITED STATES PATENTS 1,880,306 Wul Oct. 4, 1932 4 Hayakawa Apr. 28, Gier Oct. 12, Hayes July 26, Scott Oct. 10, Gier July 21, Rice et al. Feb. 27, Smith Mar. 18, 

